RISE OF THE SUPERBUGS
Bacteria, viruses and fungi are fighting back against our antibiotics. How can scientists defend us from these increasingly dangerous pathogens?
WORDS SCOTT DUTFIELD
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DID YOU KNOW?
Global use of antibiotics is expected to rise to 107,472 tonnes by 2030
One of the greatest threats to humankind’s survival is a problem we started over 100 years ago. In 1910 the world’s first antibiotic, Salvarsan, was sent out into the world to tackle syphilis, a sexually transmitted infection caused by a bacterium called Treponema pallidum. However, the discovery of penicillin in 1928 marked the true beginning of the golden age of antibiotics. Until around the 1970s, the world erupted with new antibiotic medications to tackle a plethora of illness-inducing bacteria. By breaking down their protective membranes, disrupting their DNA and halting their growth, these medications can make easy work of destroying their targets. However, in the wake of the antimicrobial revolution, a new threat has emerged.
Did you know?
Bacterium populations can double every 4 to 20 minutes
When bacteria, along with viruses or fungi, become resistant to the effects of antimicrobial medicine, it’s known as antimicrobial resistance (AMR), with antibiotic resistance being the most common form of AMR. Every antibiotic used in clinical practice now has at least one strain of bacteria that’s resistant to it, making them increasingly difficult to treat. Commonly known as ‘superbugs’, these defiant microbes get their powers of antimicrobial resistance from mutations in their DNA that lead to changes in the structure of the enzymes, proteins and membranes that antimicrobials target. Some bacteria have even developed ‘biochemical pumps’ to evict antibiotics that enter their cells.
OBLITERATING BACTERIA
How antibiotics take down their microscopic foes
1 HALTING PROTEIN PRODUCTION
Some antibiotics inhibit the production of proteins in bacteria, preventing them from growing, which leads to their death.
2 DNA DISRUPTION
By binding with the enzyme that transcribes bacterial DNA, some antibiotics stop DNA replication, causing bacteria to die.
3 BREAKING DOWN WALLS
The production of a cell wall-building polymer called peptidoglycan can be inhibited by some antibiotics. This causes the wall to open up, leading to osmotic lysis, where water fills the cell and pops it like a water balloon.
4 MEMBRANE MELTDOWN
Antibiotics can bind to the membranes of bacteria, reducing their functionality and causing them to redirect protein production to the membrane for growth and replication.
5 MESSING WITH METABOLISM
By inhibiting enzymes involved in bacteria’s production of metabolites for DNA production, some antibiotics prevent them from growing.